Gennevilliers, France — She emerges Venus-like out of a mist of hairspray with tousled hair, a shimmering 50,000-euro Chanel jacket and a 1,000-watt smile.

“Hello daarling,” says Mouna Ayoub huskily with the warm familiarity of old friends (even though we’ve met only once before) – walking around a decor of gigantic silver oyster shells and blue glass buoys to kiss me.

The billionaire divorcee’s claim to fame: owning the world’s largest collection of haute couture – a 1,600-piece wardrobe in which each gown costs between 50,000 and 290,000 euros ($70,000-$400,000). She never wears the same dress twice, and sometimes never at all.

The couture diva may hide it well, but she’s stressed today.

She’s working hard to prepare an auction of the sparkling sea-themed contents of her old yacht, the Phocea, and has ditched her nicotine patches and gone back to Marlboro Lights.

The Lebanese socialite is perhaps the best-known member of an uber-elite group of superrich women who keep alive haute couture, the 150-year-old Parisian tradition of making astronomically-priced, made-to-measure gowns. She’s also perhaps its most eccentric.

Her wardrobe alone may be enough to bankroll a small country. But she still prefers to take a 60-cent coffee from the machine in the auction warehouse in Gennevilliers, near Paris, instead of ordering in.

It’s glamour mixed with down-to-earth.

She doesn’t even have time for a proper lunch, and offers me one of the egg sandwiches that she produces from a bag with her well-manicured hand sporting fingerless gloves and a huge rose-shaped diamond ring.

Lying around her (and the egg sandwiches) in the warehouse outside Paris are trinkets resembling the cavern of a billionaire Little Mermaid that lined the inside of what was, until 2004, the largest sailing yacht in the world that she refurbished for $17 million.

The 56-year-old has friends in high places. Her good friend King Carlos of Spain was a frequent sleepover visitor on her yacht and fashion designer pal Karl Lagerfeld once stripped her naked for a photo-shoot.

She’s also a couture philanthropist. She has just donated what’s been described as the most expensive dress ever made to Paris’ Musee de la Mode – a gold Chanel traffic-stopper that cost over 300,000 euros ($412,000).

Ayoub’s is a living rags-to-riches fairytale. It goes like this: beautiful but impoverished waitress in Paris spotted by a billionaire prince charming who falls in love and sweeps her feet to a life of luxury and glamour.

Ayoub now wears couture every time she has a public engagement before stashing the gown away in a sleepy French village to be preserved forever.

But even this Lebanese Cinderella has moments when reality bites.

Take when her yacht scraped a rock along Corsica’s coast in 2002, and she nearly drowned. In a panic, she boarded a lifeboat with the bare essentials: a Jean Paul Gaultier gown to look chic for rescue, and a Louis Vuitton bag with $9.6 million of jewels inside. When the captain throttled up suddenly, the lifeboat capsized – and she was thrown into the chilly waters. Fortunately, she saw her jewel-filled bag floating meters (feet) away.

“I would have gone diving for it at the bottom of the ocean if it had sank, but luckily the bag was made from a new patent leather that floated,” she said.

(“I took off my gown and swam naked to the bag,” she revealed in a post-interview SMS. “I have a feeling I am confessing to a priest.”)

For a sense of her fabulous wealth, instead of taking a bank loan to do up the Phocea, she raised the money by selling off a diamond she’d bought, “The Mouna,” which just happens be the largest yellow diamond ever graded.

Ayoub first met her fairytale prince when she was a 20-year-old working in a late-night Lebanese restaurant who, in her own words, “had no money at all.”

He was Nasser Al-Rashid, a multi-billionaire businessman 20 years her senior and close adviser at the time to Saudi Arabia’s late King Fahd. Soon after the fateful encounter, she swapped the apron for a satin gown and cleaning scrubs for the diamond-studded slippers she’s been wearing ever since.

Fast forward four decades. Each couture house, from Chanel to Jean Paul Gaultier via Christian Dior, has their very own Mouna mannequin that they can tailor the clothes to when she is not available for a fitting. (“It’s a must,” she said.)

“I just love haute couture. It’s my only passion. I wear haute couture every time I go out in public,” she said, explaining that she never wears the same dress twice as she’s frequently photographed.

Couture has always been a secretive club – in which buyers shy away from lifting the lid on how many millions they spend on dressing.

Not Ayoub.

She’s become an unofficial couture ambassador in recent years, and is dismissive of the buyers who fear the tax repercussions of talking about their wanton spending.

“Everyone was afraid of taxes. I’m not afraid of taxes,” she said emphatically – perhaps because she can afford to live in tax-haven Monaco.

As Ayoub speaks, her makeup artist and hair guru swoops in at regular intervals – often in midsentence – attacking her with clouds of powder and jets of spray. But she keeps talking, unfazed.

“Others spend millions of dollars losing it on a blackjack table. … Some other people deal with arms. But there is nothing shameful about buying couture,” she said, saying that her spending has helped the couture industry continue in the face of critics consistently sounding its death knell.

With so many dresses, it’s perhaps unsurprising that she frequently runs out of space in her home in Monaco.

“In Monaco, I am really suffocating. I have bought another apartment just for the couture,” she said, dead serious.

The rest of her couture she safeguards with high security in a tiny village in central France called Braslou in special boxes, like sleeping beauties.

The boxes are designed so that the garments are perfectly preserved, to be worn perhaps by women in centuries to come: “No light, no dust, no moths, no humidity, no nothing; so they can be left there dormant forever.”

She loves the couture with a touching innocence, talking about it as if it were surrogate family.

But then she’ll crack a joke with a cigarette-scraped huskiness – showing that this Cinderella may be more grounded than you think.

“Couture is my art,” she said, shrugging. “But when I go shopping, I usually wear jeans.”